package com.io.client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import sun.misc.BASE64Decoder;

public class RSAEncrypt {

    private static final String DEFAULT_PUBLIC_KEY=
            "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDLBxnOozDVJdbsf/LfFuk1f9mJ\r" +
                    "DWTY+yz+TS7hJcAbd0xreBsH/h04e+oMSGAHJAhlTbBSOD80MHhaSlz9IogpQWdg\r" +
                    "av/8JWofzhA4LZheDiLUtwoLqQ1K68K3jhljZqP8Gm7ZV/wjC2/cPWw/EgTrTI/O\r" +
                    "NI2HWoxiL1uo2sfY/QIDAQAB";

    private static final String DEFAULT_PRIVATE_KEY=
            "MIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBAMsHGc6jMNUl1ux/\r" +
                    "8t8W6TV/2YkNZNj7LP5NLuElwBt3TGt4Gwf+HTh76gxIYAckCGVNsFI4PzQweFpK\r" +
                    "XP0iiClBZ2Bq//wlah/OEDgtmF4OItS3CgupDUrrwreOGWNmo/wabtlX/CMLb9w9\r" +
                    "bD8SBOtMj840jYdajGIvW6jax9j9AgMBAAECgYALDz32pakZU1Bb3bRrNqJJicdd\r" +
                    "0d72eug+ihHNrfLDDEKbcBV43/zTgNyFAsRIX0wdyJecQvgeba2AraBXIbRtAfp3\r" +
                    "JUljIN1ddnF9+/ZVsusLAHcTzRkwVH6qzqNGZpuYJBuUFsNrDUIzHWMi+3VqUPTc\r" +
                    "D74ItOAkIEGfAmvYOQJBAPbV6eytJKTjhmZFc7Q7uYnv/gwsy9QiAfZSskY24Igw\r" +
                    "3B96qhJlDkxmT9lXWQmvNO5eMeAnPdkWh25w19raqn8CQQDSkM7/70fHoBqjYp2l\r" +
                    "p6yZ8eBPyd5wUAFF0r3oplhISsVcpCTHIaKuT6cYoEYUWnYXHi0jWA5+9iQnn0nB\r" +
                    "DGaDAkEAvuAGh84Qcy26xaVZZvt0a7VZWCLf8AfoSooCcAeJs+dMoU8i6xyYZP4N\r" +
                    "Kz2/jZyeKuJOYU8XJaOlUQMT+Jp1kwJBAIV4sR3eSPuq6vfCHPfSb0At5+frqAo9\r" +
                    "THE8ApEkUDWS38O3cHChS4N+jga4IXPpW42P3UDYImgsEgLjn1a1S40CQQCAtHlr\r" +
                    "Uz58y3uWGFIfWf2YOeCLYvp2xjD708IlGx4e5R95JDRr4KCETB2I0qFMLsvY5smu\r" +
                    "FEMmQ8bup5mUG0A+";

    /**
     * 私钥
     */
    private RSAPrivateKey privateKey;

    /**
     * 公钥
     */
    private RSAPublicKey publicKey;

    /**
     * 字节数据转字符串专用集合
     */
    private static final char[] HEX_CHAR= {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};


    /**
     * 获取私钥
     * @return 当前的私钥对象
     */
    public RSAPrivateKey getPrivateKey() {
        return privateKey;
    }

    /**
     * 获取公钥
     * @return 当前的公钥对象
     */
    public RSAPublicKey getPublicKey() {
        return publicKey;
    }

    /**
     * 随机生成密钥对
     */
//    public void genKeyPair(){
//        KeyPairGenerator keyPairGen= null;
//        try {
//            keyPairGen= KeyPairGenerator.getInstance("RSA");
//        } catch (NoSuchAlgorithmException e) {
//            e.printStackTrace();
//        }
//        keyPairGen.initialize(1024, new SecureRandom());
//        KeyPair keyPair= keyPairGen.generateKeyPair();
//        this.privateKey= (RSAPrivateKey) keyPair.getPrivate();
//        this.publicKey= (RSAPublicKey) keyPair.getPublic();
//    }

    /**
     * 从文件中输入流中加载公钥
     * @param in 公钥输入流
     * @throws Exception 加载公钥时产生的异常
     */
    public void loadPublicKey(InputStream in) throws Exception{
        try {
            BufferedReader br= new BufferedReader(new InputStreamReader(in));
            String readLine= null;
            StringBuilder sb= new StringBuilder();
            while((readLine= br.readLine())!=null){
                if(readLine.charAt(0)=='-'){
                    continue;
                }else{
                    sb.append(readLine);
                    sb.append('\r');
                }
            }
            loadPublicKey(sb.toString());
        } catch (IOException e) {
            throw new Exception("公钥数据流读取错误");
        } catch (NullPointerException e) {
            throw new Exception("公钥输入流为空");
        }
    }


    /**
     * 从字符串中加载公钥
     * @param publicKeyStr 公钥数据字符串
     * @throws Exception 加载公钥时产生的异常
     */
    public void loadPublicKey(String publicKeyStr) throws Exception{
        try {
            BASE64Decoder base64Decoder= new BASE64Decoder();
            byte[] buffer= base64Decoder.decodeBuffer(publicKeyStr);
            KeyFactory keyFactory= KeyFactory.getInstance("RSA");
            X509EncodedKeySpec keySpec= new X509EncodedKeySpec(buffer);
            this.publicKey= (RSAPublicKey) keyFactory.generatePublic(keySpec);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此算法");
        } catch (InvalidKeySpecException e) {
            throw new Exception("公钥非法");
        } catch (IOException e) {
            throw new Exception("公钥数据内容读取错误");
        } catch (NullPointerException e) {
            throw new Exception("公钥数据为空");
        }
    }

    /**
     * 从文件中加载私钥
     * @param keyFileName 私钥文件名
     * @return 是否成功
     * @throws Exception
     */
    public void loadPrivateKey(InputStream in) throws Exception{
        try {
            BufferedReader br= new BufferedReader(new InputStreamReader(in));
            String readLine= null;
            StringBuilder sb= new StringBuilder();
            while((readLine= br.readLine())!=null){
                if(readLine.charAt(0)=='-'){
                    continue;
                }else{
                    sb.append(readLine);
                    sb.append('\r');
                }
            }
            loadPrivateKey(sb.toString());
        } catch (IOException e) {
            throw new Exception("私钥数据读取错误");
        } catch (NullPointerException e) {
            throw new Exception("私钥输入流为空");
        }
    }

    public void loadPrivateKey(String privateKeyStr) throws Exception{
        try {
            BASE64Decoder base64Decoder= new BASE64Decoder();
            byte[] buffer= base64Decoder.decodeBuffer(privateKeyStr);
            PKCS8EncodedKeySpec keySpec= new PKCS8EncodedKeySpec(buffer);
            KeyFactory keyFactory= KeyFactory.getInstance("RSA");
            this.privateKey= (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此算法");
        } catch (InvalidKeySpecException e) {
            throw new Exception("私钥非法");
        } catch (IOException e) {
            throw new Exception("私钥数据内容读取错误");
        } catch (NullPointerException e) {
            throw new Exception("私钥数据为空");
        }
    }

    /**
     * 加密过程
     * @param publicKey 公钥
     * @param plainTextData 明文数据
     * @return
     * @throws Exception 加密过程中的异常信息
     */
    public byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception{
        if(publicKey== null){
            throw new Exception("加密公钥为空, 请设置");
        }
        Cipher cipher= null;
        try {
            cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] output= cipher.doFinal(plainTextData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此加密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        }catch (InvalidKeyException e) {
            throw new Exception("加密公钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("明文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("明文数据已损坏");
        }
    }

    public byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData) throws Exception{
        if(privateKey== null){
            throw new Exception("加密公钥为空, 请设置");
        }
        Cipher cipher= null;
        try {
            cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            byte[] output= cipher.doFinal(plainTextData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此加密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        }catch (InvalidKeyException e) {
            throw new Exception("加密公钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("明文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("明文数据已损坏");
        }
    }


    /**
     * 解密过程
     * @param privateKey 私钥
     * @param cipherData 密文数据
     * @return 明文
     * @throws Exception 解密过程中的异常信息
     */
    public byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception{
        if (privateKey== null){
            throw new Exception("解密私钥为空, 请设置");
        }
        Cipher cipher= null;
        try {
            cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] output= cipher.doFinal(cipherData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此解密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        }catch (InvalidKeyException e) {
            throw new Exception("解密私钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("密文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("密文数据已损坏");
        }
    }

    public byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData) throws Exception{
        if (publicKey== null){
            throw new Exception("解密私钥为空, 请设置");
        }
        Cipher cipher= null;
        try {
            cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            byte[] output= cipher.doFinal(cipherData);
            return output;
        } catch (NoSuchAlgorithmException e) {
            throw new Exception("无此解密算法");
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
            return null;
        }catch (InvalidKeyException e) {
            throw new Exception("解密私钥非法,请检查");
        } catch (IllegalBlockSizeException e) {
            throw new Exception("密文长度非法");
        } catch (BadPaddingException e) {
            throw new Exception("密文数据已损坏");
        }
    }


    /**
     * 字节数据转十六进制字符串
     * @param data 输入数据
     * @return 十六进制内容
     */
//    public static String byteArrayToString(byte[] data){
//        StringBuilder stringBuilder= new StringBuilder();
//        for (int i=0; i<data.length; i++){
//            //取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移
//            stringBuilder.append(HEX_CHAR[(data[i] & 0xf0)>>> 4]);
//            //取出字节的低四位 作为索引得到相应的十六进制标识符
//            stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);
//            if (i<data.length-1){
//                stringBuilder.append(' ');
//            }
//        }
//        return stringBuilder.toString();
//    }


    public static void main(String[] args){
        RSAEncrypt rsaEncrypt= new RSAEncrypt();
        //rsaEncrypt.genKeyPair();

        //加载公钥
        try {
            rsaEncrypt.loadPublicKey(RSAEncrypt.DEFAULT_PUBLIC_KEY);
            System.out.println("加载公钥成功");
        } catch (Exception e) {
            System.err.println(e.getMessage());
            System.err.println("加载公钥失败");
        }

        //加载私钥
        try {
            rsaEncrypt.loadPrivateKey(RSAEncrypt.DEFAULT_PRIVATE_KEY);
            System.out.println("加载私钥成功");
        } catch (Exception e) {
            System.err.println(e.getMessage());
            System.err.println("加载私钥失败");
        }

        //测试字符串
        String encryptStr= "hello  test  is sa test";

        try {
            //加密
            //byte[] cipher = rsaEncrypt.encrypt(rsaEncrypt.getPrivateKey(), encryptStr.getBytes());
            //解密
            byte[] plainText = rsaEncrypt.decrypt(rsaEncrypt.getPrivateKey(), "jM6pCKQCoW5jwfmvcH8u4WOBFkL75fEHzxAEg1k7E6fx/1czEwUX6e552ObKf9EsRkHefzaeb0R1xpV2Cl0rRvH+hB0iI87Jd2Zc87yJyXwtz9MNp/XBzFlDabLFGgy2uD7GTLv5a/cj0RBTmmwenTNitpnX+/mADF0jLDgVZJ0=".getBytes());
//            System.out.println("密文长度:"+ cipher.length);
//            System.out.println(RSAEncrypt.byteArrayToString(cipher));
//            System.out.println("明文长度:"+ plainText.length);
//            System.out.println(RSAEncrypt.byteArrayToString(plainText));
            System.out.println(new String(plainText));
        } catch (Exception e) {
            System.err.println(e.getMessage());
        }
    }
}

